Biogenic metallic nanoparticles as enzyme mimicking agents

Catalytic and biological properties of Ag-Pt bimetallic nanoparticles: composition-dependent activity and cytotoxicity

Due to their unique elemental compositions and interface coupling effects, bimetallic nanoparticles (BNPs), a class of nanoalloys, have attracted significant attention for applications in biomedicine, environmental remediation, and catalysis. BNPs, formed via the combination of two metal ions under light or thermal conditions, exhibit enhanced catalytic properties due to synergistic interactions between constituent metals, which result in optimized electronic structures, increased active sites, and reduced activation energy for catalytic reactions. However, BNPs may pose potential toxicity risks to organisms through bioaccumulation and environmental exposure. In this study, Ag-Pt nanoparticles (AP NPs) with varying molar ratios were synthesized and characterized to elucidate the relationship between composition, catalytic activity, and cytotoxicity. Catalytic assays revealed that AP NPs exhibited remarkable oxidase-like activity. Cytotoxicity tests revealed dose- and composition-dependent effects, with the AP55 (Ag : Pt at 5 : 5 ratio) exhibiting the highest cytotoxicity compared to monometallic counterparts at equivalent concentrations. Notably, the proportion of Ag in the AP NPs was identified as the dominant factor influencing catalytic activity and cytotoxicity. Mechanistic investigations attributed this cytotoxicity to the interplay of peroxidase-like catalytic activity, oxidative stress, and lysosomal ion release, disrupting cellular redox homeostasis and triggering apoptosis. Enzymatic assays further confirmed reductions in antioxidant defenses, including superoxide dismutase (SOD) and catalase (CAT) activities, amplifying reactive oxygen species (ROS) generation and oxidative damage. These findings underscore the critical role of catalytic behavior in mediating biological interactions and cytotoxic effects of BNPs. We establish a relationship between composition, oxidase-like activity, and cytotoxicity, providing insights into their potential biomedical applications and paving the way for the rational design of multifunctional nanomaterials with tunable biological effects.

Biogenic metallic nanoparticles: from green synthesis to clinical translation

Biogenic metallic nanoparticles (NPs) have garnered significant attention in recent years due to their unique properties and various applications in different fields. NPs, including gold, silver, zinc oxide, copper, titanium, and magnesium oxide NPs, have attracted considerable interest. Green synthesis approaches, utilizing natural products, offer advantages such as sustainability and environmental friendliness. The theranostics applications of these NPs hold immense significance in the fields of medicine and diagnostics. The review explores intricate cellular uptake pathways, internalization dynamics, reactive oxygen species generation, and ensuing inflammatory responses, shedding light on the intricate mechanisms governing their behaviour at a molecular level. Intriguingly, biogenic metallic NPs exhibit a wide array of applications in medicine, including but not limited to anti-inflammatory, anticancer, anti-diabetic, anti-plasmodial, antiviral properties and radical scavenging efficacy. Their potential in personalized medicine stands out, with a focus on tailoring treatments to individual patients based on these NPs' unique attributes and targeted delivery capabilities. The article culminates in emphasizing the role of biogenic metallic NPs in shaping the landscape of personalized medicine. Harnessing their unique properties for tailored therapeutics, diagnostics and targeted interventions, these NPs pave the way for a paradigm shift in healthcare, promising enhanced efficacy and reduced adverse effects.

Nanotechnology in action: silver nanoparticles for improved eco-friendly remediation

Nanotechnology is an exciting area with great potential for use in biotechnology due to the far-reaching effects of nanoscale materials and their size-dependent characteristics. Silver and other metal nanoparticles have attracted a lot of attention lately because of the exceptional optical, electrical, and antimicrobial characteristics they possess. Silver nanoparticles (AgNPs) stand out due to their cost-effectiveness and abundant presence in the earth's crust, making them a compelling subject for further exploration. The vital efficacy of silver nanoparticles in addressing environmental concerns is emphasized in this thorough overview that dives into their significance in environmental remediation. Leveraging the distinctive properties of AgNPs, such as their antibacterial and catalytic characteristics, innovative solutions for efficient treatment of pollutants are being developed. The review critically examines the transformative potential of silver nanoparticles, exploring their various applications and promising achievements in enhancing environmental remediation techniques. As environmental defenders, this study advocates for intensified investigation and application of silver nanoparticles. Furthermore, this review aims to assist future investigators in developing more cost-effective and efficient innovations involving AgNPs carrying nanoprobes. These nanoprobes have the potential to detect numerous groups of contaminants simultaneously, with a low limit of detection (LOD) and reliable reproducibility. The goal is to utilize these innovations for environmental remediation purposes.

AIE fluorogen-based oxidase-like fluorescence nanozyme-integrated smartphone for monitoring the freshness authenticity of soy products

Food safety concerns about the authenticity of soy product freshness have increased due to high demand from public. Developing an accurate and convenient monitoring method for freshness authenticity is crucial for safeguarding food safety. From this motive, this study employed PtPd NPs to encapsulate tetraphenylethylene (TPE) for engineering an AIE-based fluorescent nanozyme (PtPd NPs@TPE) with oxidase-like activity, achieving the ratiometric fluorescence monitoring of putrescine (PUT) to judge the freshness authenticity of soy products. In this design, PUT acted as an antioxidant and inhibited the oxidation process of PtPd NPs@TPE to o-phenylenediamine (OPD), leading to the reduction of oxidative product 2,3-diaminophenothiazine (DAP) alone with the weaken of yellow fluorescence from DAP at 552 nm and bright of bule fluorescence from PtPd NPs@TPE at 442 nm. On this basis, a ratiometric fluorescence strategy integrated with smartphone-based sensor was developed for PUT with acceptable results to combat food freshness fraud of soy products.